linux/fs/ecryptfs/super.c

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/**
* eCryptfs: Linux filesystem encryption layer
*
* Copyright (C) 1997-2003 Erez Zadok
* Copyright (C) 2001-2003 Stony Brook University
* Copyright (C) 2004-2006 International Business Machines Corp.
* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
* Michael C. Thompson <mcthomps@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/key.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/file.h>
#include <linux/crypto.h>
#include "ecryptfs_kernel.h"
struct kmem_cache *ecryptfs_inode_info_cache;
/**
* ecryptfs_alloc_inode - allocate an ecryptfs inode
* @sb: Pointer to the ecryptfs super block
*
* Called to bring an inode into existence.
*
* Only handle allocation, setting up structures should be done in
* ecryptfs_read_inode. This is because the kernel, between now and
* then, will 0 out the private data pointer.
*
* Returns a pointer to a newly allocated inode, NULL otherwise
*/
static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
{
struct ecryptfs_inode_info *inode_info;
struct inode *inode = NULL;
inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
if (unlikely(!inode_info))
goto out;
ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
mutex_init(&inode_info->lower_file_mutex);
atomic_set(&inode_info->lower_file_count, 0);
inode_info->lower_file = NULL;
inode = &inode_info->vfs_inode;
out:
return inode;
}
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static void ecryptfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct ecryptfs_inode_info *inode_info;
inode_info = ecryptfs_inode_to_private(inode);
INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
}
/**
* ecryptfs_destroy_inode
* @inode: The ecryptfs inode
*
* This is used during the final destruction of the inode. All
* allocation of memory related to the inode, including allocated
* memory in the crypt_stat struct, will be released here.
* There should be no chance that this deallocation will be missed.
*/
static void ecryptfs_destroy_inode(struct inode *inode)
{
struct ecryptfs_inode_info *inode_info;
inode_info = ecryptfs_inode_to_private(inode);
BUG_ON(inode_info->lower_file);
ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
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call_rcu(&inode->i_rcu, ecryptfs_i_callback);
}
/**
* ecryptfs_statfs
* @sb: The ecryptfs super block
* @buf: The struct kstatfs to fill in with stats
*
* Get the filesystem statistics. Currently, we let this pass right through
* to the lower filesystem and take no action ourselves.
*/
static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_sb->s_op->statfs)
return -ENOSYS;
return lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
}
/**
* ecryptfs_evict_inode
* @inode - The ecryptfs inode
*
* Called by iput() when the inode reference count reached zero
* and the inode is not hashed anywhere. Used to clear anything
* that needs to be, before the inode is completely destroyed and put
* on the inode free list. We use this to drop out reference to the
* lower inode.
*/
static void ecryptfs_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
end_writeback(inode);
iput(ecryptfs_inode_to_lower(inode));
}
/**
* ecryptfs_show_options
*
* Prints the mount options for a given superblock.
* Returns zero; does not fail.
*/
static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct super_block *sb = mnt->mnt_sb;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
struct ecryptfs_global_auth_tok *walker;
mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
list_for_each_entry(walker,
&mount_crypt_stat->global_auth_tok_list,
mount_crypt_stat_list) {
if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
else
seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
}
mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
seq_printf(m, ",ecryptfs_cipher=%s",
mount_crypt_stat->global_default_cipher_name);
if (mount_crypt_stat->global_default_cipher_key_size)
seq_printf(m, ",ecryptfs_key_bytes=%zd",
mount_crypt_stat->global_default_cipher_key_size);
if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)
seq_printf(m, ",ecryptfs_passthrough");
if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
seq_printf(m, ",ecryptfs_xattr_metadata");
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
seq_printf(m, ",ecryptfs_encrypted_view");
if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
seq_printf(m, ",ecryptfs_unlink_sigs");
if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
seq_printf(m, ",ecryptfs_mount_auth_tok_only");
return 0;
}
const struct super_operations ecryptfs_sops = {
.alloc_inode = ecryptfs_alloc_inode,
.destroy_inode = ecryptfs_destroy_inode,
.drop_inode = generic_drop_inode,
.statfs = ecryptfs_statfs,
.remount_fs = NULL,
.evict_inode = ecryptfs_evict_inode,
.show_options = ecryptfs_show_options
};